The present invention relates to the field of pressurized fluid systems. More particularly, the present invention relates to an apparatus for charging a fluid system with an appropriate fluid.
Pressurized fluid systems are very common in the industrialized society. All such systems are similar in that they are pressurizable, closed systems. As such, the systems generally operate optimally within a certain pressure range. If the internal pressure falls below this range, the system needs to be xe2x80x9crechargedxe2x80x9d with the appropriate fluid.
Some systems, for example, air conditioning/refrigeration coolant lines, are designed to remain closed during use. Theoretically, these systems should not require recharging because they should not loose nor consume their contents. In practice, however, the internal pressure inside such systems tends to drop over time due to leakage, however minor, or degradation/decomposition of the pressurized material. Accordingly, the systems commonly require periodical recharging. Some systems, such as automotive air conditioning systems, can be recharged at the on-site operation using more sophisticated tools. However, other systems must be recharged off-site with limited tooling.
Oftentimes, these systems require that a certain amount of fluid within a given range be present in the system at any time. Excessive fluid can actually damage some systems due to the accompanying increase in pressure within the system. It is difficult using presently available charging apparatuses to determine the amount of fluid that is being added to the system. Aside from the concern of adding too much fluid, the attempt to add an excessive amount of fluid may result in overspill and fluid waste. Some of these fluids, such as refrigerant and refrigerant oils, are relatively expensive and add to the cost of servicing the charged system.
Accordingly, there is a need for a apparatus for adding fluids to charged systems which allows the user to readily determine the amount of fluid that has been added to the system. What is also needed is such an apparatus that can be operated by a handle when out in the field or alternatively by power tools when those are readily accessible. The present invention fulfills these needs and provides other related advantages.
The present invention resides in an apparatus for adding fluids to charged systems. The apparatus includes a cylinder having a first cap attached to a first end thereof. A second cap is removably attached to a second end of the cylinder. A threaded rod has a portion extending through and engaging a threaded aperture of the first cap. The rod includes a driving nut formed at an exterior end thereof. Typically, the driving nut is in the form of a hex nut. An interior end of the rod is disposed within the cylinder. A piston is attached to the interior end of the rod and engages the cylinder to form a variable volume reservoir within the cylinder. Preferably, the cylinder is transparent and includes graduated markings for determining the amount of fluid within the variable volume reservoir at any given time.
A hose assembly is in fluid communication with the variable volume reservoir and extends through the second cap. The hose assembly typically includes a flexible hose and a charging port adapter at an end thereof opposite the second cap.
The apparatus includes a handle detachably connectable to the driving nut for adjusting the position of the piston. Alternatively, a socket attachment of a power tool may be engaged with the driving nut in order to rotate the rod and adjust the position of the piston within the cylinder.
Use of the present invention is advantageous over similar devices in that the user of the apparatus can see through the transparent cylinder and easily gauge, using the graduated markings on the cylinder, the amount of fluid within the variable volume reservoir at any given time. Also, the user is not limited to use of the detachable handle, but may conveniently connect a power tool to the driving nut of the rod to more speedily charge the system in question.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.